const arr = new Array(7).fill([]);
arr[0][0] = 1;
console.log(arr);

let arr1:Array<Array<number>> = [];
for (let index = 0; index < 7; index++) {
  arr1.push([]);
}

for (let index = 0; index < arr.length; index++) {
  arr[index][0] = index;
  arr1[index][0] = index;
}
console.log(arr);
console.log(arr1);
